Simply attach it to the sound hole of your guitar to vary the sound effects such as reverb, echo, and chorus. No need to drill any holes. This item is in excellent condition, having only been viewed. When removing the speaker, the double-sided tape was too strong and the speaker came off, so I replaced it with one I had on hand. It works without any problems. I am selling this at a reduced price due to this minor issue. The color is matte black. Please search on Amazon for more details.